shapesynth vs K7D
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
shapesynth
Create unique retro-inspired sounds by drawing oscillator waveforms. This polyphonic synthesizer offers extensive modulation options, built-in effects, and recording capabilities. Seamlessly integrate with other music apps and hardware for a versatile creative experience.
- Draw custom oscillator waveforms
- 16-voice polyphony
- Arpeggiator and stereo delay
- Resonant filter
- Parameter modulation via keyboard, MPE, accelerometer
- Tape recorder with infinite overdubs
- Inter-app audio and AUv3 support
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Shape is a polyphonic synthesiser allowing the user to draw the shape of the oscillator waveform. The first half of the oscillator is represented by 32 blocks and the second half is its mirror, generating all sorts of possible raw retroish sounds. 16 pages per oscillator allows to interpolate between different shapes. Add effects like arpeggio, stereo delay and a resonant filter and record your sounds on a classic tape. Modulate any parameter with keyboard, MIDI MPE or the device accelerometer. Connect to other apps with AudioBus, IAA, AUv3 and midi. +++ 16 voice polyphony +++ 2 oscillators, draw your own shape +++ 3 oscillator mixing functions (add, subtract or multiply) +++ Lfo modulation with ADSR: envelope, pitch, duty cycle, square, page or filter +++ Record on tape with infinite overdubs (save, load, import, export) +++ Arpeggiator +++ Stereo delay +++ Resonant filter (low, band and high pass) +++ Modulate any parameter using keyboard, MIDI MPE or accelerometer (Built in or Sphero) +++ Mini linear sequencer with euclidean rhythm +++ On screen 25 key stylophone style keyboard +++ AudioBus, Inter App Audio and AUv3 +++ Ableton link or AUv3 host sync +++ CoreMIDI, IAA MIDI, Bluetooth MIDI, limited MPE and MIDI out +++ Audio Paste, files app drag’n drop or open with
K7D
This app offers a vintage tape delay effect with analog emulation and modern controls. It recreates classic hardware echo machines for a warm, characterful sound. Use it standalone or as an AUv3 plugin in iOS DAWs.
- Analog modeled dual playhead delay
- Modeled microphone input with saturation
- Normal and Ping Pong modes
- High pass and Low pass feedback filters
- Powerful LFO time modulation
- BPM syncable delay time
- MIDI delay time modulation
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K7D is a powerful and affordable, vintage tape delay effect plugin for iOS. K7D recreates the hardware echo machines of the past using Imaginando’s signature style of obsessive analog emulation, but with an enhanced level of control from a sleek, modern interface. Using this approach allows a whole new world of creative possibilities, while still retaining a warm, full-bodied analog sound, bursting with character and personality. To give K7D it’s distinctive analog flavour, we studied and analysed the tiny details of what makes classic hardware delays great, and painstakingly recreated every subtle nuance for a fantastically authentic sound. Available as a standalone app and audio unit plugin, you can use it digital audio stations for iOS such as Garage Band, AUM, Cubasis, Auria, Audiobus, etc. Features - 1ms to 1 sec. dual playhead analog modeled delay with noise, tape distortion and mechanical vibration models - Modeled microphone input with pre-amp saturation - Normal and Ping Pong modes - Optimized gain staging and saturation algorithms for very musical results - Delay time spread between heads and stereo width control - High pass and Low pass filter on feedback path - Powerful LFO bipolar time modulation with multiple waveforms (sine, triangular, saw, square, sample and hold and filtered sample and hold) and possibility of inverted LFO phase on second play head (for added stereo imaging) - Delay time syncable with BPM - Possibility of delay time modulation via incoming midi notes - Oscilloscope visualisation of audio waveform and LFO waveform - Built-in patch manager - Audiounit compatible
Screenshots
Verdict
The clearest difference is rating: shapesynth at 4.9 against K7D's 4.6. shapesynth also leads on iOS requirement (9.0 vs 17.0). K7D's advantage is review sentiment (80% vs 65%) and ratings volume (79 vs 24). On update cadence, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
shapesynth costs $4.99 and K7D $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
shapesynth holds the better App Store score, 4.9 against 4.6. Both are backed by a comparable volume of ratings — 24 and 79 respectively. Written reviews complicate that: 65% of shapesynth's written reviews are positive against 80% of K7D's, so the app with the better star average is not the one people write more warmly about.
shapesynth ships an update every 2 months, K7D every 3 months. The most recent releases landed on September 25, 2026 and September 22, 2026 respectively.
| Parameter | shapesynth | K7D |
|---|---|---|
| Price | $4.99 | $3.99 — better |
| Rating | 4.9 (24 ratings) — better | 4.6 (79 ratings) |
| Positive reviews | 65.0% of reviews | 79.5% of reviews — better |
| Number of ratings | 24 | 79 — better |
| Update frequency | Every 2 months — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 9.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 8 MB | 113 MB |
| Age rating | 4+ | 4+ |
| Developer | Erik Sigth | Imaginando Lda |
Customer experience
shapesynth
K7D
In-app purchases
shapesynth
No in-app purchases
K7D
No in-app purchases








